Please forgive my general ignorance on this topic, I've spent the better part of the last two days referencing older threads and trying to confirm, but figured it would be best to ask the experts here to be certain.

I recently picked up a Dahon Speed Uno. I live in an apartment on the third floor and wanted something I could transport relatively easy (both up the stairs and in my car). The idea was to get back into biking, since I really haven't been on a bike since I was about 16. I also intrigued by the simplicity of the Speed Uno's design and the generally positive reputation Dahon had. No gears meant less things for me to break or have to fix down the road.

I've enjoyed riding it so far, and have been pushing myself to go a little further each day. I also realize being surrounded by hills that this bike was not intended for going up hills. I can't say I completely mind this, it's definitely a great workout for my legs, and this is not the only reason I've recently considered an upgrade. The other reasons are that I think it would be nice to have the option of getting this bike moving a little faster than stock form, and if it's possible to have two gears without having to manually shift them or run cables (i.e. SRAM Automatic), I could really see myself benefiting from such an upgrade. I do understand there are other variables involved with how fast a bike can go, however, I would imagine that freeing up the energy I'm presently using on hills might translate into more power on flat roads.

What I'm trying to confirm is exactly what is needed to complete the upgrade to an automatic 2-speed system to help me justify the costs involved. Based on my research and extremely limited knowledge, I was looking at picking up this SRAM 2A hub with the coaster brake, hoping it would be a close to direct fit to the setup I currently have on my Speed Uno. I also had the following questions:

- Based on this hub configuration and my current platform, would I also need a new rim or completely new tire/rim combination? I see that some people on here have ordered complete setups from Universal Cycles, is this the way I should be leaning?
- Is the 36h model w/rear coaster brake the one I should be looking at, or does it not matter based on the smaller size of my tire (20")?
- Would the chain I have on there now be sufficient for the upgrade or should this also be replaced?
- What is an estimated cost to for parts/labor to have this upgrade completed through a professional shop? There apparently is a decent shop down the street from me called Cycle Loft that might be able to do this, I just haven't called yet because I don't want to sound like a complete idiot.

I realize there are a lot of people who will say I should have just gone with a geared-model folder instead, and they're probably right, but I do enjoy this bike a lot and going through the process of upgrading and figuring out what works/doesn't will be helpful for me in the end. In the short period of time I've owned the bike and been on this forum I've already learned a lot more than I knew before. Any constructive feedback is welcome and greatly appreciated.